This invention is directed to an improved electrical connector, of the modular plug type, that offers decreased Near End Cross Talk (NEXT) and decreased insertion loss at high transmission frequencies through a decreased capacitance coupling between adjacent terminals.
The design of modular plugs and their complementary modular jacks or receptacles, are dictated by FCC regulations to ensure mating engagement. Notwithstanding such regulations, the present invention preferably teaches a unique terminal array for a modular plug that meets the requirements for matability with approved modular jacks.
By way of brief background, an approved modular jack includes a housing having a cavity therein of a size for receiving a modular plug, where the cavity is provided with plural, cantilevered spring contacts which correspond to a like plurality of contact terminals in the mating modular plug. A typical modular plug receives discrete, insulated, stranded or solid conductors in conductor-receiving troughs or slots formed in a dielectric housing. Flat, blade-like metallic terminals are then inserted into individual vertically oriented slots in the housing in a generally side-by-side arrangement with contact portions thereof extending into engagement with the conductors. When the plug is inserted into a modular jack, the cantilevered portions of the terminals in the jack engage portions of associated terminals in the plug.
Since FCC approval of the architecture of modular jacks and plugs, efforts have continued toward improving the components, such as the introduction of a strain relief to the conductors, as exemplified by U.S. Pat. No. 4,607,905. Additionally, to facilitate loading and termination of the conductors in the modular plug, load bars or wire organizers were developed, an example thereof being taught by U.S. Pat. No. 4,713,023. An earlier version is disclosed in U.S. Pat. No. 4,601,530, assigned to the assignee hereof. The latter patent teaches a preloaded wire organizer for a modular type plug. Specifically, the patent teaches the process of preloading wires into a wire holder which locates the leading ends of the wires at the same pitch as the troughs or slots in the connector housing. The wire holder, supported by the wires, is then inserted into and along the cavity of the housing until it abuts a tapered throat at the entrance to the troughs. Further advance of the assembly feeds the discrete wires through the wire holder into the respective troughs guided by the throat, while the wire holder remains adjacent the tapered throat.
With these prior art improvements, the architecture of the plug and jack were maintained. It was not until relatively recently that communication equipment and needs arose requiring improved performance at higher operating frequencies. From this evolved new technical standards, known in the art as Category 5 products, where operating frequencies may be 100 MHz or higher. However, development of Category 5 products, such as modular plugs and jacks, had to proceed within the guidelines of the FCC regulations, particularly the architecture.
U.S. Pat. No. 5,186,647 represents a recent approach to improve operating performance in a modular jack, for example, by imposing an overlapping arrangement of selected spring contacts. Recently, Stewart Connector Systems, Inc. of Glen Rock, Pa., introduced a Category 5 performing modular plug utilizing a sliding wire management or load bar, where such bar contains two rows, each with four through holes, to receive the standard eight wires of a cable. To use the management bar, the user is advised to arrange the wires in two equal sets, and cut each set of four at a 45.degree. angle such that no two wires are of the same length. With the prepared wires, the wires are individually fed into the holes of the wire organizer, in sliding engagement therewith, then trimmed to the same length. For the loading step, the wire organizer is first pushed to the end of the trimmed wires, then inserted into the connector housing. In the fashion of U.S. Pat. No. 4,601,530, noted earlier, when the wire organizer can no longer move forward, the wires are pushed beyond the wire organizer into a position to be individually terminated, as known in the art.
The present invention, while continuing to adhere to the FCC regulations on architectural requirements, discovered a way to achieve Category 5 performance through a unique terminal contact arrangement in the modular plug. This discovery will become apparent in the further description which follows, particularly when read in conjunction with the accompanying drawings.